The phase and aggregation behavior of aqueous solutions of ethoxylated perfluorocarbon alcohols (C(x)F(2x+1)C(2)H(4)EO(4-7) with x = 6-12) is reported. With increasing concentration, an L(1)*-phase, an L(1)*/L(alpha)-two-phase region, an L(alpha)-phase, and an L(2)-phase are observed. The dilute part of the L(1)*/L(alpha)-two-phase region (concentration range less than or equal to 3 wt%) contains unilamellar vesicles. The existence of vesicles is shown by TEM micrographs, conductivity measurements, and theological data. The size of the vesicles was determined by quasielastic and static light scattering as well as by electric birefringence. For surfactant concentrations greater than or equal to 20 wt%, the L(alpha)-phase has a yield stress value. The yield stress value is explained on the basis of the existence of multilamellar vesicular aggregates. It was possible to produce a yield stress value in the L(alpha)-phase with much lower concentrations by slightly charging up the bilayers with the anionic surfactant C8F17CO2Li.